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Kia Sorento 2.5 CRDi 2010 - Misfire under load - Fixed #

Posted by Alwyn James on September 13, 2013, 1:36 pm

Year of Manufacture *: 2010
Engine Size and Code *: 2.5crdi
( Optional ) ECU Type: Bosch
( Optional ) Scanner Used: Launch/Pico
( Optional) Fault Codes: None

Hi all.Just looking for any pointers on this vehicle.It has a misfire under load,not a constant misfire but random single events.I have scoped it to death and cant find a glitch when fault occurs.
Have scoped rail pressure,cam/crank,boost and airflow and injector triggers/current and all ok at time of fault with no dropouts.Think next step might be to have injectors checked.A wps pressure sensor would be great for this fault!Anybody had this kind of fault before.
Regards Alwyn

Re: Kia Sorento misfire under load

Posted by Tony Ludford <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT5539' width='330' height='300' border=0 style='border:none;'> on September 14, 2013, 9:20 am, in reply to "Kia Sorento misfire under load"
Tony Ludford

Is this an old shape Sorento or new? The information below relates to old shape:

Are you sure it's a misfire? Or is it the 4wd system locking up between 30-45mph....

If it's got AUTO on the 4wd selector switch, it's more likely to be the torque on demand system transferring power to the front wheels under load, and an issue is causing a "shunt" type feel when driving.
To confirm the fault, once started remove F14 (TCCS) and roadtest (note this is also an immobiliser fuse so may not start if removed Key on/engine off)

If the fault has gone:
All tyres must be the same rolling cirumference, any difference of more than 2mm in tread will cause symptoms.
Remove the front propshaft and make sure the sliding joint is free.
Check Transfer box fluid level is correct manual states Dexron 111 but I'm sure they've introduced a special T.O.D oil for these now....

Check axle levels and backlash 3-15mm is acceptable at driveflange.
Check no brakes are binding, especially after roadtest.

If all of the above don't cure it, a new clutch pack inside the transfer case may fix it, but after several issues we now only fit a complete unit.
I have a test sheet for these if you want, I can email it later.

Tony

Re: Kia Sorento misfire under load

Posted by alwyn james <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1546' width='330' height='300' border=0 style='border:none;'> on September 14, 2013, 1:50 pm, in reply to "Re: Kia Sorento misfire under load"
Alwyn James

Thanks for your reply tony.It is indeed the last of the old shape models so your information could indeed be relevant.The fault is most noticeable at low speeds when accelerating hard escpecially in 2nd gear and once up to speed in 4th and 5th it flies with no noticeable fault.I will give your test a go on monday morning.Does this fault leave a fault code in transmission/4wd edu?Also if you have time i would be grateful if you could send me the test sheet.
Regards Alwyn

Re: Kia Sorento misfire under load

Posted by Tony Ludford <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT5539' width='330' height='300' border=0 style='border:none;'> on September 14, 2013, 4:43 pm, in reply to "Re: Kia Sorento misfire under load"
Tony Ludford

It doesn't always set a fault code, as it's not seeing a fault! Have you tried light acceleration up a small gradient, it can be quite difficult to feel, but once you can detect it, you will always feel it.
A very light shudder through the car, almost like it's had a single misfire event. The harder you drive, the more liable it is to transfer torque to the front wheels to prevent rear wheel-spin. This will emphasize any faults in the system.

Sent the TSB.

Tony

Re: Kia Sorento misfire under load

Posted by Alwyn James <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1546' width='330' height='300' border=0 style='border:none;'> on September 14, 2013, 6:45 pm, in reply to "Re: Kia Sorento misfire under load"
Alwyn James

Thanks for that Tony,it does seem like exact symptoms i have.The funny thing is its a traders vehicle he took in as a part ex and now a retired farmer wants to buy it.He's been out in it 3 times and because he doesn't drive very hard he hasn't detected a fault!Worst case senario what is the price of a new unit?
Regards Alwyn

Re: Kia Sorento misfire under load

Posted by Tony Ludford <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT5539' width='330' height='300' border=0 style='border:none;'> on September 15, 2013, 1:03 am, in reply to "Re: Kia Sorento misfire under load"
Tony Ludford

"cough cough" about £1700 if I remember correctly.

Another thing you can do, if removing the TCCS works, and confirms tyre fault rather than transmission or propshaft fault. Is to swop the tyres front to rear, the fault may then only be noticeable on hard deceleration....

But I didn't tell you that.

Re: Kia Sorento misfire under load

Posted by Alwyn James <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1546' width='330' height='300' border=0 style='border:none;'> on September 16, 2013, 10:11 am, in reply to "Re: Kia Sorento misfire under load"
Alwyn James

Tony you were bang on the money,fault has disapeared with fuse removed!Vehicle currently on winter tyres so will try road tyres and re-evaluate.
Regards Alwyn

Fixed #

Posted by alwyn James on September 16, 2013, 6:59 pm, in reply to "Re: Kia Sorento misfire under load"
Edited by board administrator September 19, 2013, 6:52 pm

Can't quite believe it but a set of road tyres has resolved the issue after the wasted time chasing an engine misfire.Many thanks to Tony for his input.
Regards Alwyn

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